I have a '97 DX Auto (I know right? The only option I have..) Anyway, no matter if the car is cold or warm the first shift from 1st to 2nd when you turn the car on is HARD and clunks; gives your whiplash. But after that it's perfectly fine.

Car had a new trans installed 13K miles ago; by the previous owner.

Also; when driving down hill it doesn't change from 3rd to 4th at any throttle level until about 38MPH. Very weird.

Could it be that I need a TPS? When there's no throttle applied the sensor reads 9.3%, and full throttle reads 90.6%. Goes smoothly between those.

 

I think you can adjust the shift cable where it connects to the throttle cable cam. The shift cable runs up from the transmission to where the throttle cable is connected to the intake manifold. I know on my del sol it fixed the slow upshifts from 1st to 2nd.